Synchronized control system for machine guns



July 8, 1930. R. c. couPLAND 1,7?0,125

` SYNCHRONIZED CONTROL SYSTEM FOR MACHINE GUNSy Filed Aug. 1. 1927 2 Sheets-Sheet l July 8, 1930. R. c. couPLAND 1,77%125 SYNCHRONIZED CONTROL SYSTEM FOR MACHINE GUNS Filed Aug. l. 192'7 2 Sheets-Sheet 2 mmm l Www/m i e me/nto@ PHE- Emuplanci Patented Julyl 8, 1930 UNITED STATES RICHARD C. COUPLAND, F DAYTO, OHIO 'SYNCHRONIZED'CONTROL SYSTEM FOR MACHINE GUNS Application mea Auguri 1, 1927. serial No. 209,893.

' f (GRANTED UNDER THE vACT 0F MARCH 8, 1883, AS AMENDED APRIL 3f), 1 928; 370 0. G. 757) The invention described herein, if patented, may be manufacturedand used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

vision for operating the sear slide from either sideof the gun, and by the necessity for frequent inspection and adjustment.

Accordingly it is the purpose of the present invention to provide a gun control assembly in which the impulse generator and trigger motor units comprise a novel arrangement of elements enabling the units to be small, light, and compact, and permitting complete flexibility between the engine and the gun.l The lindividual units may be disassembled without interfering with the assembly and the connecting cable can be readily attached, de-

tached, and adjusted.

Further objects of the invention are to provide an improved hydraulic control valve, a

v system of lubrication for the impulse generator, a novel one piece floating trigger controlled by areciprocating cam and a direct acting impulse cable.

electrical control, including an electrically actuated plunger in which complete adjustment of the plunger is provided for, and control switches in the form of buttons or other- Wise mounted on the control gear or other changing the synchronizer proper.

With the foregoing and other objects in view my invention resides. in the novel ar'- rangement and combination of parts and in the vdetails of construction hereinafter described and claimed, it being understood that This invention relates 'to a synchronized' The invention further aims to provide anl changes in the precise embodiment of the inyention herein disclosed maybe 4made with- 1n the scope of what is claimed Without departing from the spirit of the invention.

A practical embodiment of the invention is illustratedI in the accompanying drawings, wherein:

Fig. 1 is a longitudinal sectional view of a gun control assembly; v

Fig. 2 -is a detailed sectional view of th trigger motor taken at right angles to Fig. 1; I

Fig. 3 is a detail sectional view of the generator showing a mechanically actuated release for the slide;

Fig. 4 is a sectional view of an electrically operated release;

Fig. 5 is a detail sectional view showing the forward displacement of the trigger;

Fig. 6 is a sectional view of the electrical button control as designed to be used on the airplane control stick.

Referring to Fig. 1 the gun control assembly consists of an impulse generator A controlled by an operating mechanism and connected to the trigger motor C by means of the impulse cable and cable housing D.

The impulse generator unit is arranged to constitute a compact integral part of the engine synchronized during assembly or after assembly thereof and consists of a housing 5 in which is mounted a driving shaft 6, receiving its energy from the engine and rotating at a speed to give a cam impulse for each blade of the propeller. The shaft runs on spaced bearings 7-7/-7 and carries a cam 8 positioned between the bearings and arranged to engage the foot 9** on one end of a cam follower 9 which is parallelto the cam shaft. Threaded in the other end of the cam follower is a plug 10 in which is secured the impulse cable 11 preferably made of piano wire and leading to the trigger motor. The cable is sheathed in a suitable tube 12 which is secured preferably by soldering or brazing to a socket 13 removably held in place by a nut 14 threaded to the genei ator housing.

The operating mechanism for controlling the cam follower 9 comprises a spring pressed plunger 15 disposed above the cam shaft` and arranged to enter a recess 16 in the follower' for the purpose of holding the follower lin inoperative position clear of the cam 8. When this condition obtains the trigger motor is inactive and the sear slide can not be actuated as will be shown in detail in describing the trigger motor unit.

. As shown in Fig. 1 the withdrawal and re-y tention of the plunger is accomplished through a hydraulic control associated with the lubrication system of the engine. The

control consists of a casing 17 having an inlet line 18 leading from the main line 19, an outlet line 2O leading to the plunger 15 and an exhaust line 21 leading to the cam shaft. A piston valve 22 having spaced heads 23-23 for the purpose of securing equalization of pressures is connected to a control grip 24 so that it may be moved against the action of a spring 25. In Fig.A 1 the piston is shown in retarded position to open and establish communication between-the inlet and outlet lines so that pressures may be transmitted to the generator and exerted on the plunger 15 to disengagel it from the slide 9. y

When the control grip 24 is released the spring 25 will restore the piston to the position indicated in dotted lines thereby interrupting communication between the inlet and the outlet lines. Such restoration of the piston closing off pressure from the main line is accomplished without diiculty by the light spring 25 because the pressure is equalized on the two heads of the piston. Withy the pressure removed the plunger 15 travels forwardly to engage the slide and displaces oil in the line 2O forcing the oil back to the valve casing where it exhausts through the line 21 and returns to the crank case by way of the generator where it lubricates the .camshaft bearings.

Lubrication is also provided for the slide 9 by means of an openig 15a in the plunger 15 whereby any oil ywhich passes behind the plunger may escape and drain to the crank case.

open-endedv housing 26 arranged to be attached to the receiver of the machine gunin a well known manner. One end of the tubing 12 is detachably connected to a nipple of the housing while the end of the impulse cable 11 within the casing extends through an adjusting screw 27 and is secured to a plug which seats in a tapered washer 29 bearing against the head of the adjusting screw. This provision is made to permit rotation of the adjusting screw. without twistingl the cable. The adjusting screw is threaded in .a reciprocally mounted cam member 30 inserted in the open-end of the housing and normally moved to the rear or inoperative` position by the spring 31. The cam is in constant engagement with a one-piece lioating trigger 32 which is disposed in a recess 33 in the housing 2.6 and when moved' inwardly actuates the sear slide The trigger motor unit C `consists of an of the gun indicated at 34. The trigger .is restored to the outward position by the spring 35.

When acted on by the cam 30 or spring 35 the trigger is constrained to rectilinear movement by the rear wall 36 of the recess 33 and by the fulcrum 37 in the front wall but it is capable of forward displacement'as indicated in Fig. `5. The provision for this displacement is necessary because the trigger reciprocates at a different frequency than the normal rate of firing the'gun and if it is in the inward position when the bolt of the gun is arriving in battery the forward face of the sear slide 34 will strike the side of the trigger and cause it to yield. lFurthermore when in discontinuing firing the operating Vmechanism B is released to hold the cam followers 9 of the generator in the inoperative position, the cam. 30 in the trigger motor willbe held forward thereby maintaining the trigger in the path of the sear slide 34 whence it will be rotated by the sear slide as the bolt arrives home after firing the last shot. It will then be in safe or inoperative position and the gun can not be fired until the operating mechanism B is again acted on.

In the modification shown in Fig. 3 the operating mechanism B is of a mechanical type and does not alter the essential characteristics of the impulse generator. The control plunger 15b corresponding to the plunger 15 in Fig. 1 and arranged in the same relative position is retracted by means of acable 38 which is secured to a hand grip 39. The socket member 40 which receives the casing of the cable 38 `and establishes a seat for the plunger spring 41 is threaded as at 42 in the generator housing.

Inl F ig. 4 an electrically controlled plunger unit 15Cl is mounted in a casing 43 whiclr replaces the plunger 15a. This unitincludes the usual coil-44 which, when energized retracts the plunger from engagement with the slide 9 and compresses the plunger spring.

The coil is energized by a suitable sourceof electrical current, Vnot shown, through any desired circuit closing means, such as,` for example, the Contact button 45 which, when -compressed, engages the contacts 46 and completes the circuit in a well known manner. The button illustrated is of the thumb operated type to be used on an airplane control stick, there being two buttons mounted side by side for the respective control of a right or left hand gun.

It is to be understood that any form of circuit control which may prove 'most convenient may be used ,and such control may be mounted on any desired part of'an aircraft.

I claim:

1. In a synchronizing gear for machine guns, an impulse generator including a housing, anengine driven cam shaft extendinginto the housing, a cam. follower mounted in the housing parallel to the cam shaft, a lplungerarranged in the housing and engagea le wlth the cam follower to hold it inoperative, a hy draulic control mechanism for the plunger and means for exhaust-ing said mechanism through the impulse generator.

2. In a synchronizing gearl for machine guns, an impulse generator including a housing, an engine driven cam shaft extendinginto the housing, a cam follower mounted in the` housing parallel to the cam shaft, a plun er -arrangedin the housing and engageable wlth the cam follower t'o hold it inoperativeand means for controlling the plunger.

3. AIn ar synchronizing gear for machine guns, an impulse generator including a housing, an impulse transmission member in the housing, a plunger for holding'said member in inoperative position, an hydraulic control mechanism for said yplunger including a valve chamber having an inlet line from a fluid source, an outlet to the plunger and an exhaustto the impulse transmission member, and a piston valve having spaced heads in the chamber.`

4. In a synchronizing gear for machine guns, an impulse generator including a housing, an impulse transmission member in the housing, a plunger for holding said member in inoperative position, and a plunger control apparatus having means for lubrlcatin'g the plunger and transmission member.

5. A trigger motor for machine guns including an open ended housing, a reciprocating trigger actuating cam in said housing and an impulse cable adj ustably secured to the eX- posed end of said cam.

RICHARD C. COUPLAND.v 

